Umbilicals are often used in the transmission of fluids and/or electric signals between the sea surface and equipment located on the sea bed. Such umbilicals generally include one or more pipes and electric conductors/wires collected in a bundle, a filler material arranged at least partly around and between the pipes and conductors/wires, and a protective sheath enclosing the pipes, conductors/wires, and filler material. To help strengthen such umbilicals, attempts have been made to use pultruded carbon fiber rods as separate load carrying elements. Exemplary umbilical designs are described in more detail, for instance, in U.S. Pat. No. 7,798,234 to Ju, et al. and U.S. Pat. No. 7,754,966 to Figenschou, which are incorporated herein in their entirety by reference thereto for all purposes. A significant problem with such rods however, it is that they rely upon thermoset resins (e.g., vinyl esters) to help achieve the desired strength properties. Thermoset resins are difficult to use during manufacturing and do not possess good bonding characteristics for forming layers with other materials.
As such, a need currently exists for an umbilical that contains pultruded fiber rods formed from a thermoplastic material, which are still capable of achieving the desired strength and durability.